In a cellular system, a base station is connected to multiple terminals. The base station allocates resources to each terminal for communication with the base station, and notifies a resource allocation message to the terminal. After receiving the resource allocation message sent by the base station, the terminal obtains, according to the resource allocation message, time-frequency resources for receiving downlink signals and sending uplink signals.
In an existing system, the time-frequency resources allocated to the terminal may be a part of time-frequency resources selected by the base station in the entire system bandwidth. The system bandwidth is a bandwidth that is preconfigured by a system and has a fixed size. In this way, the resource allocation indication information for indicating the time-frequency resources of the terminal includes an uplink resource allocation message and downlink resource allocation indication information. The system needs to indicate the allocated time-frequency resources in the system bandwidth of a fixed size, and therefore, the size of the indication information increases with the increase of the system bandwidth, which causes that redundancy of physical layer signaling increases with the increase of the system bandwidth. That is to say, the size of the indication information is limited by the system bandwidth.